Microgenerazione
Microgeneration is the small-scale generation of heat and electric power by individuals, small businesses and communities to meet their own needs, as alternatives or supplements to traditional centralized grid-connected power. Although this may be motivated by practical considerations, such as unreliable grid power or long distance from the electrical grid, the term is mainly used currently for environmentally conscious approaches that aspire to zero or low-carbon footprints. It differs from micropower in being principally concerned with heavy, fixed power plants rather than mobility. Technologies and set-up Microgeneration technologies include small scale wind turbines, Micro hydro, photovoltaic solar systems, Plant Microbial Fuel Cells, ground source heat pumps, and Micro Combined Heat and Power (MicroCHP) installations.Microgeneration technology options The power plant In addition to the electricity production plant (e.g. wind turbine, solar panel, ...), infrastructure for energy storage and power conversion and a hook-up to the regular electricity grid is usually needed and/or foreseen. Although a hookup to the regular electricity grid is not essential, it helps to decrease costs by allowing financial recompensation schemes. In the developing world however, the start-up cost for this equipment is generally too high, thus leaving no choice but to opt for alternative set-ups.Practical Action - Energy for rural communities Extra equipment needed besides the power plant The whole of the equipment required to set up a working system and for an off-the-grid generation and/or a hook up to the electricity grid herefore is termed a balance of systemEquipment required for off-grid-operation and is composed of the following parts with PV-systems: Energy storage apparatus A major issue with off-grid solar and wind systems is that the power is often needed when the sun is not shining or when the wind is calm, this is generally not required for purely grid-connected systems: * a series of deep cycle, stationary or sealed maintenance free batteries (the most common solution) Practical Action - Energy for rural communities (includes short description batteries) or other means of energy storage (e.g. hydrogen fuel cells, Flywheel energy storage, pumped-storage hydroelectricity, compressed air tanks, ...)Hydrogen fuel cells for domestic energy generation * a charge controller for charging the batteries or other energy storage For converting DC battery power into AC as required for many appliances, or for feeding excess power into a commercial power grid: * an inverter or grid-interactive inverter. The whole is also sometimes referred to as "power conditioning equipment" Safety equipment * groundings, transfer switches or isolator switches and surge protector. The whole is also sometimes referred to as "safety equipment" Usually, in microgeneration for homes in the developing world, a prefabricated house-wiring systems (as wiring harnesses or prefabricated distribution units) is used instead .Mentioning of prefabricated house-wiring and its systems Simplified house-wiring boxes, known as wiring harnesses can be simply bought and drilled in the wall without requiring much knowledge on the wiring itself. As such, even people without technical expertise are able to install them. In addition, they are also comparatively cheap and offer safety advantages.Benefits of wiring harnasses * battery meters (for charging rate and voltage), and meters for power consumption and electricity provision to the regular power grid Wind turbine specific With wind turbines, hydroelectric plants, ... the extra equipment needed Balance-of-system for wind turbinesExtra equipment needed with wind turbines (Gaiam)Extra equipment needed with wind turbines (EnergyAlternatives)System layout + schematic of diy wind turbine is more or less the same as with PV-systems (depending on the type of wind turbine used,Schematic showing certain components as controllers built into the wind turbine itself yet also include: * a manual disconnect switch * foundation for the tower * grounding system * shutoff and/or dummy-load devices for use in high wind when power generated exceeds current needs and storage system capacity. Vibro-wind power A new wind energy technology is being developed that converts energy from wind energy vibrations to electricity. This energy, called Vibro-Wind technology, can use winds of less strength than normal wind turbines, and can be placed in almost any location. The vibro-wind setup is also more economically viable. A prototype consisted of a panel mounted with oscillators made out of pieces of foam. The conversion from mechanical to electrical energy is done using a piezoelectric transducer, a device made of a ceramic or polymer that emits electrons when stressed. The building of this prototype was led by Francis Moon, professor of mechanical and aerospace engineering at Cornell University. Moon's work in Vibro-Wind Technology was funded by the Atkinson Center for a Sustainable Future at Cornell. Turbine-free wind power was showcased in NY Times' 10th Annual Year in Ideas. A video explaining how it works can be found here. Possible set-ups Several microgeneration set-ups are possible. These are: *Off-the-grid set-ups which include: ** Off-the grid set-ups without energy storage (e.g., battery, ...) ** Off-the grid set-ups with energy storage (e.g., battery, ...) ** Battery charging stations Battery charging stations explained *Grid-connected set-ups which include: ** Grid-connected set-ups without financial recompensation scheme ** Grid-connected set-ups with net metering ** Grid connected set-ups with net purchase and sale Net purchase and sale explained All set-ups mentioned can work either on a single power plant or a combination of power plants (in which case it is called a hybrid power system). Note: For safety reasons, there are legal requirements that all domestic grid-connected set-ups must automatically switch off when there is a failure of the mains power supply. This means that they can NOT supply electricity during power cuts. The appropriate supply regulations should be consulted when planning a system. For more about this, see the article on the condition of islanding. Costs Depending on the set-up chosen (financial recompensation scheme, power plant, extra equipment), prices may vary. According to Practical Action, microgeneration at home which uses the latest in cost saving-technology (wiring harnesses, ready boards, cheap DIY-power plants (e.g. DIY wind turbines), ...) the household expenditure can be extremely low-cost. In fact, Practical Action mentions that many households in farming communities in the developing world spend less than $1 for electricity per month. .Households reducing their energy ependitures to $1 a month using renewable microgeneration However, if matters are handled less economically (using more commercial systems/approaches), costs will be dramatically higher. In most cases however, financial advantage will still be done using microgeneration on renewable power plants; often in the range of 50-90% EERE mentioning 50-90% financial advantage using microgeneration In the UK, the government offers both grants and feedback payments to help businesses, communities and private homes to install these technologies. Businesses can write the full cost of installation off against taxable profits whilst homeowners receive a flat rate grant or payments per kW h of electricity generated and paid back into the national grid. Community organisations can also receive up to £200,000 in grant funding.UK Grant Funding information In the UK, the Microgeneration Certification Scheme provides approval for Microgeneration Installers and Products which is a mandatory requirement of funding schemes such as the Feed in Tariffs and Renewable Heat Incentive. Comparison with large-scale generation Microgeneration can dynamically balance the supply and demand for electric power, by producing more power during periods of high demand and high grid prices, and less power during periods of low demand and low grid prices. This "hybridized grid" allows both microgeneration systems and large power plants to operate with greater energy efficiency and cost effectiveness than either could alone. Domestic self-sufficiency Microgeneration can be integrated as part of a self-sufficient house and is typically complemented with other technologies such as domestic food production systems (permaculture and agroecosystem), hydrogen or other extra electricity generation systems for self-sufficient transport, rainwater harvesting, composting toilets or even complete greywater treatment systems. Domestic microgeneration technologies include: photovoltaic solar systems, small scale wind turbines, ground source heat pumps, micro combined heat and power installations, biodiesel and biogas. by Green EcoSys & Electron Solar Energy]] Private generation decentralizes the generation of electricity and may also centralize the pooling of surplus energy. While they have to be purchased, solar shingles and panels are both available. Capital cost is high, but saves in the long run. With appropriate power conversion, solar PV panels can run the same electric appliances as electricity from other sources.Fritsch, Al, and Paul Gallimore. Healing Appalachia: Sustainable Living Through Appropriate Technology. Lexington, KY. The UP of Kentucky, 2007. Passive solar water heating is another effective method of utilizing solar power. The simplest method is the solar (or a black plastic) bag. Set between 1 and 5 gallons out in the sun and allow to heat. Perfect for a quick warm shower.http://www.motherearthnews.com/Green-Homes/2007-10-01/Build-Your-Own-Solar-Water-Heater.aspx The ‘breadbox’ heater can be constructed easily with recycled materials and basic building experience. Consisting of a single or array of black tanks mounted inside a sturdy box insulated on the bottom and sides. The lid, either horizontal or angled to catch the most sun, should be well sealed and of a transparent glazing material (glass, fiberglass, or high temp resistant molded plastic). Cold water enters the tank near the bottom, heats and rises to the top where it is piped back into the home. You can acquire designs through the National Center for Appropriate Technology or design your own. Wind turbines can be purchased for a wide range of prices. It takes a little more technical knowledge to assemble one yourself but plans are available Mother Earth News. Ground source heat pumps utilize stable ground temperatures to maintain heat in the pumps. Typically ground source heat pumps have a high initial cost and can’t be created by the average homeowner. As with other electric motors, they require an external power source and are usually powered by non-renewable energy sources. Fuel Biodiesel is an alternative fuel that can power diesel engines and can be used for domestic heating. Numerous forms of biomass, including soybeans, peanuts, and algae (which has the highest yield), can be used to make biodiesel. Recycled vegetable oil (from restaurants) can also be converted into biodiesel.http://www.motherearthnews.com/Green-Transportation/2006-02-01/Biodiesel.asp Biogas is another alternative fuel, created from the waste product of animals. Though less practical for most homes, a farm environment provides a perfect place to implement the process. By mixing the waste and water in a tank with space left for air, methane produces naturally in the airspace. This methane can be piped out and burned, and used for a cookfire. Government policy Policy-makers were accustomed to an energy system based on big, centralised projects like nuclear or gas-fired power stations. A change of mindsets and incentives are bringing microgeneration into the mainstream. Planning regulations may also require streamlining to facilitate the retrofitting of microgenerating facilities onto homes and buildings. Most of developed countries, including Canada (Alberta), the United Kingdom, Germany, Israelhttp://www.israel-electric.co.il/Static/WorkFolder/HomeClients/pv-hahachlata-hamelea.pdf State of Israel Public Utilities Authority Decision #216 (Hebrew) and USA have laws allowing microgenerated electricity to be sold into the national grid. Alberta, Canada In January 2009, the Government of Alberta‘s Micro-Generation Regulation came into effect. This regulation is a set of rules that allows Albertans to generate their own environmentally friendly electricity and receive credit for any power they send into the electricity grid. See how microgeneration works in Alberta. United States The United States has inconsistent energy generation policies across its 50 states. State energy policies and laws may vary significantly with location. Some states have imposed requirements on utilities that a certain percentage of total power generation be from renewable sources. For this purpose, renewable sources include wind, hydroelectric, and solar power whether from large or microgeneration projects. Further, in some areas transferrable "renewable source energy" credits are needed by power companies to meet these mandates. As a result, in some portions of the United States, power companies will pay a portion of the cost of renewable source microgeneration projects in their service areas. These rebates are in addition to any Federal or State renewable-energy income-tax credits that may be applicable. In other areas, such rebates may differ or may not be available. United Kingdom The UK Government published its Microgeneration StrategyUK Department of Trade and Industry Microgeneration Strategy in March 2006, although it was seen as a disappointment by many commentators.Home power plan 'disappointment' BBC News report on the UK Department of Trade and Industry Microgeneration Strategy In contrast, the Climate Change and Sustainable Energy Act 2006 has been viewed as a positive step.Sustainable energy groups welcome parliamentary initiative to reduce climate change emissions, article by micropower on the Climate Change and Sustainable Energy Act 2006 To replace earlier schemes, the Department of Trade and Industry (DTI) launched the Low Carbon Buildings Programme in April 2006, which provided grants to individuals, communities and businesses wishing to invest in microgenerating technologies. These schemes have been replaced in turn by new proposals from the Department for Energy and Climate Change (DECC) for clean energy cashback via Feed-In Tariffs Clean energy cashback from Feed-In Tariffs for generating electricity from April 2010 and the Renewable Heat Incentive Renewable Heat Incentive for generating renewable heat from 28 November 2011. Feed-In Tariffs are intended to incentivise small-scale (less than 5MW), low-carbon electricity generation. These feed-in tariffs work alongside the Renewables Obligation (RO), which will remain the primary mechanism to incentivise deployment of large-scale renewable electricity generation. The Renewable Heat Incentive (RHI) in intended to incentivise the generation of heat from renewable sources. They also currently offer up to 21p per kWh from December 2011 in the Feed-in Tariff for photovoltaics plus another 3p for the Export Tariff - an overall figure which could see a household earning back double what they currently pay for their electricity.http://www.fitariffs.co.uk/FITs/principles/export/ On 31 October 2011, the Government announced a sudden cut in the feed-in tariff from 43.3p/kWh to 21p/kWh with the new tariff to apply to all new solar PV installations with an eligibility date on or after 12 December 2011.Department of Energy and Climate Change press release (31 October 2011).http://www.decc.gov.uk/en/content/cms/news/pn11_091/pn11_091.aspx Prominent British Politicians who have announced they are fitting microgenerating facilities to their homes include the Conservative party leader, David Cameron, and the Labour Science Minister, Malcolm Wicks. These plans included small domestic sized wind turbines. Cameron, before becoming Prime Minister in the 2010 general elections, had been asked during an interview on BBC One’s The Politics Show on the October 29th 2006 if he would do the same should he get to 10 Downing Street. “If they’d let me, yes,” he replied.The Times (October 30, 2006 ). Cameron: I'd have a No 10 wind turbine. Retrieved 2010-05-15. In the December 2006 Pre-Budget Reporthttp://www.hm-treasury.gov.uk/pre_budget_report/prebud_pbr06/prebud_pbr06_index.cfm Pre-Budget Report 2006, Section 7.31. the Government announced that the sale of surplus electricity from installations designed for personal use, would not be subject to Income Tax. Legislation to this effect has been included in the Finance Bill 2007.Office of Public Sector Information; Finance Act 2007 Chapter 11, Part 2, Environment. Retrieved 2010-05-14. In popular culture Microgeneration has been popularised by several movies, TV-shows, and magazines. Movies such as The Mosquito Coast, Jericho, The Time Machine, and Beverly Hills Family Robinson have done a great deal in raising interest to the general public. More specialised magazines such as OtherPower and Home Power give more practical advice and guidance.OtherPower and Home Power as popular diy microgeneration magazines Websites such as Instructables and Practical Action are increasing the popularity of microgeneration by proposing DIY-solutions which can decrease the cost of microgeneration. Note See also * Appropriate technology; includes a list of technology usable to set up microgeneration * Deep cycle battery (the type of batteries to be used in domestic, off-grid systems) * Distributed generation * Domestic energy consumption (offers calculations to set up microgeneration-plants) * Emergency power system * Home fuel cell * Hydrogen station * MicroFIT * Micropower * Photovoltaic array * Small scale wind power * Small hydro External links Systems' self-sufficiency parts * Microgeneration.com - Basic information on setting up microgeneration at home * USDA EERE's off-grid generation page * Information on precise domestic power consumption calculations to create partial/or completely off-grid systems * Practical action's info on setting-up microgeneration at home * Earthship Biotincture's info and practical (low-cost) modules on setting up microgeneration systems in practice * VillageEarth AT SourceBook: Contains information on microgeneration systems and set-ups * BlueEnergy; provides general schematic of parts required for self-sufficient energy generation system, also provides info on DIY equipment (windturbine in set-ups) * Domestic Wind Turbine Test Videos * MAKE WIND PAY - Interesting document on wind logging for small scale wind turbines * Hope Farm Information on Wind Power - Page on securing incentives, building, and monitoring power generated by small scale wind on Upstate NY farm. UK-related *Wind Turbine Generators, Durham University, UK *http://www.berr.gov.uk/energy/sources *Renewable Heat Incentive *Environment and Greener Living *Microgeneration Certification Scheme Information Installers *Ofgem information on Feed-in Tariffs *Feed-in Tariffs. Government’s Response to the Summer 2009 Consultation *Micropower Council - In the UK they act as the industry's main contact point for government, opinion formers, the press, and the public *Small is Beautiful, commentary on UK microgeneration issues *Power Predictor - Low-cost and easy-to-use site assessment *Building for a Future magazine: Microgeneration - Good or bad? *Microgeneration Yorkshire - support for microgeneration sector in Yorkshire *Professional Wind Speed Logger for Small scale Wind Turbine projects Academic paper focusing on India *http://www.sciencedirect.com/science/article/pii/S0301421509008866 Kumar, A., Shankar, R., Momaya, K. and Gupte, S. (2010), “The Market for Wireless Electricity: the Case of India”, Energy Policy, 38(3), 1537–1547 categoria:Economia solidale